Mystery engine component

[rydfly]

Can somebody please tell me, what is this thing? I don't have and engine parts guide to view and it's not externally obvious (to me at least) what it's function is on my C-145-2.

Thanks!

[mit]

Looks like it could be a terrorist attempt to install a part with out FAA approval!

[rydfly]

Okay, so I'll pose the question another way... for those of you without this strange doo-hickey, what goes in this spot on your engine?

[W.J.Langholz]

I was going to say something like "It's a heifer ring on a bull-shaft" but then I didn't want to be a smart a$$......

This is good, I can't wait for the experts to chime in on this one NOW I'm curious as well. You should win a prise for the best question of the year or something

W.

[lowNslow]

Looks like it might of been something for a controllable prop Do your log books show your aircraft ever having a different prop?

[bagarre]

I'll give it a shot:
IPC for the C145, O-300,A,B,C,d
Figure 1 Shows a propeller control for O-300C and O-300E engines.

It doesn't show that part in particular. My guess is, this was someone's attempt to plug the hole for use with a fixed pitch prop.

[Bruce Fenstermacher]

As stated that is the prop control boss the device is mounted to. Some kind of prop control no doubt but not the normal lever seen on a C-145-2H or 0-300-B.

[bagarre]

My mistake. I read the usable code directly.
The IPC usable code for those parts is CE which equates to the C142-2H and O-300-B

Here is a previous post with pictures of what it's supposed to have:

http://www.cessna170.org/forums/viewtop ... f=2&t=4955

[rydfly]

So do I understand correctly that there was an option for some C-145's to have a mechanical prop? I believe my engine is orignal to the airframe, a '53 170B.

Also, when I look at the topic linked in the above post, I don't see any picture attached of what the device should look like. I'd like to have the correct component installed if possible.

[bagarre]

The O-300-B and C-145-2H could accommodate a mechanical prop.
I don't think these motors were ever stock on a 170B tho. There are others on this forum that can answer this tho.
The first photo shows the assembly that was there. The IPC barely shows the parts.
If you have a fixed pitch prop, I don't know if you need any of the parts to be legal. You might be able to block off the hole with a plate.

[GAHorn]

I suspect you have a -2H engine (or perhaps a O-300-B) as others have noted. (Take a look at your engine data-plate and tell us which model engine you have.)

Anyway.... the front of ALL our engines have an oil passageway which is ordinarily plugged with those two allen-socket plugs you see in front of that oil-manifold installed and plugged on your engine. Some variants of these engines were used as Ground Power Units by gov't and military. Many of those engines had accessories which were oil-pressure regulated...or used external oil coolers....which required access to the oil gallery in this area. This device appears to be such a manifold. I've never seen one on an airplane before this one, but I have seen GPU engines converted to aircraft use, although not legally on certificated airplanes.

[rydfly]

My data plate says simply "C-145", yet my original logbook states "C-145-2H"

So then, the question becomes... what should I put into this hole to keep things legal?

[c170b53]

I think George is right...again. That plug Fwd of the mystery part is the front end of the oil gallery and the part appears to be a manifold. From memory the part that fits in there on a "B" 0-300 to provide oil Px is simply a round barrel with two parallel flats. When the arm (protrudes out of a cover plate similar to the photo) on the end of the barrel is rotated the two flats parallel to the oil passage allow oil fwd to a passage that allows oil to flow through to the crankshaft and then to the prop. When rotated back the barrel closes off the oil PX when the flats are perpendicular to the oil gallery. I'll try and locate the parts but I may have given them away.
Here's the cover that I believe you often see if the parts have been removed. I'm not sure you need to remove your part if its not causing you any grief.

IMG_0022.JPG

The P/N is 533965 and there's a gasket as well.

[Bruce Fenstermacher]

So do I understand correctly that there was an option for some C-145's to have a mechanical prop? I believe my engine is orignal to the airframe, a '53 170B.

Also, when I look at the topic linked in the above post, I don't see any picture attached of what the device should look like. I'd like to have the correct component installed if possible.

Yes there is a McCauley 2 positon prop that is approved for our 170s and it requires this control to actually work. The prop is pretty rare and we only know one person flying one. This prop was not an option from Cessna but I'll bet you could have specified the 2H engine (0-300-B didn't exist at that time) when ordering your Cessna and then have the prop installed. Another interesting fact the Aeromatic Prop approved for our 170s also requires the 2H engine and control though the control is not actually used to control this prop because it is automatic.

So yes we could probably find other airframes with an original to it 2H engine and maybe even a 0-300-B installed in a '56 though the B engine was never approved by Cessna.

Here is the picture you couldn't see.

propcontrol[1].jpg

The control lever and barrel are hanging partly out of the engine.

As for the cover Jim showed, earlier in this thread. That is the wrong cover I believe and won't fit this side but fits the opposite side were a fuel pump might be installed.

If you can't find the parts, I'd have a cover made for it. I'm pretty sure you don't actually need the barrel installed to block the oil but I'd have to check to be sure. Someone here probably already knows.

[GAHorn]

If it were mine I wouldn't do a thing and leave what's there.